Machine tool, in particular multi-spindle turning machine

ABSTRACT

The present disclosure relates to a machine tool, in particular multi-spindle turning machine, comprising a machine frame, a turret body being rotatably supported by the machine frame, a plurality of workpiece spindles being arranged on the turret body, each of the workpiece spindles having a workpiece receiving portion for receiving a respective workpiece on one side of the turret body facing a working space of the machine tool, and a torque motor for driving a rotation of the turret body. The torque motor is arranged at a back end portion of the turret body opposite to the side of the turret body facing the working space of the machine tool, and a position locking mechanism for locking a rotational position of the turret body is arranged at a front end portion of the turret body on the side of the turret body facing the working space of the machine tool.

The present disclosure related to a machine tool, in particular amulti-spindle turninh machine.

BACKGROUND

In the prior art, machine tools, in particular multi-spindle turningmachines, are known, including multiple workpiece spindles supported ona rotary drum (turret or turret body), wherein the rotary drum/turretbody is configured to rotate/index the rotary drum/turret body around alongitudinal axis thereof.

For example, in EP 2 163 334 B2, a multi-spindle turning machine isdescribed that has multiple workpiece spindles supported on a rotarydrum, wherein the rotary drum is configured to rotate/index the rotarydrum around a longitudinal axis thereof, and, for each workpiece spindlethere is provided a tool assembly holding one or more tools. Forrelative movement between the workpieces received at the workpiecespindles and the tools of the tool assemblies, the spindles are movablein a Z-direction being axially arranged with the respective spindleaxis. Further, each of the tool assemblies is configured to move in aradial X-direction with respect to the longitudinal rotation axis of thedrum and in a tangential Y-direction with respect to the longitudinalrotation axis of the drum.

A drive mechanism for indexing a drum/turret of a multi-spindle turningmachine using a torque motor is described in US 2013/0025408 A1.However, in US 2013/0025408 A1 the torque motor is arranged in a centerportion of a full body turret, so that heat generated by the torquemotor is easily dissipated through the turret body and thermal effectsmay affect the achievable level of accuracy in the machining processeson the turret side facing the workspace. Furthermore, the torque motoris described to not only drive the rotation of the drum/turret, but isfurther described to be used to lock the drum position during the actualmachining of workpieces when the drum is held in a machining positionduring the machining of workpieces, however, this may actually lead tofurther increased thermal effects due to heat generated by the torquemotor being kept energized during the machining operations.

It is an object of the present disclosure to further develop the conceptof the multi-spindle turning machine of EP 2 163 334 B2, taking intoaccount the above, and particularly to enhance the machining options ofthe multi-spindle turning machine, to provide a compact machine concept,allowing for more flexible, accurate, efficient and reliable machiningoperations, and/or to improve accuracy and/or stability of the machinetool.

SUMMARY

In view of one or more of the above objects, there is proposed a machinetool, in particular multi-spindle turning machine, according to claim 1.The dependent claims relate to preferred exemplary embodiments.

According to some aspects, there may be provided a machine tool, inparticular multi-spindle turning machine, comprising a machine frame, aturret body being rotatably supported by the machine frame, a pluralityof workpiece spindles being arranged on the turret body, each of theworkpiece spindles having a workpiece receiving portion for receiving arespective workpiece on one side of the turret body facing a workingspace of the machine tool.

In some exemplary aspects, each of the workpiece spindles may preferablybe movable and/or slidable in a longitudinal direction (Z-direction),e.g. in parallel with the longitudinal rotational axis of the turretbody and/or in parallel with the respective spindle axis. Accordingly,an advantageously compact design with independent accurate spindlemovement in spindle axis direction can be provided.

Furthermore, in some exemplary aspects, there may be provided, for eachworkpiece spindle, a respective tool post assembly for holding one ormore tools. The tool post assembly may preferably be movable in one ormore, preferably two directions (X- and/or Y-directions), transverselyor perpendicularly to the longitudinal direction. Accordingly, anadvantageously compact design with independent accurate tool movementrelative to the spindle axis, in particular in one or more directionstransversely or perpendicularly to the respective spindle axis, can beprovided.

In some preferred aspects, the machine tool may include a torque motorfor driving a rotation of the turret body. Accordingly, a compact,efficient, precise and reliable drive mechanism for driving the rotationof the turret body can be provided.

In some preferred aspects, the torque motor may be arranged at a backend portion of the turret body, e.g. opposite to the side of the turretbody facing the working space of the machine tool. Advantageously, suchexemplary aspect allows to provide the torque motor on an opposite sideas the working space area having the tool holder assemblies and otherequipment, such that a balanced compact overall design can be provided,and the potential heat generating drive (torque motor) is provided at adistance to the working space area so that heat generation has minimalor almost no influence on equipment and assemblies at the side of theworking space area, where high machining precision is required.

In some preferred aspects, a position locking mechanism for locking arotational position of the turret body may be arranged at a front endportion of the turret body, e.g. on the side of the turret body facingthe working space of the machine tool. Accordingly, the position lockingmechanism is provided close (adjacent) to the working space area, wherehigh machining precision is required, and therefore the position lockingmechanism can lock positions very accurately and precisely to enableoptimal exact spindle positioning during the machining operations.

In some preferred aspects, a position detecting mechanism fordetermining the rotational position of the turret body may be arrangedat the front end portion of the turret body on the side of the turretbody facing the working space of the machine tool. Accordingly, theposition detecting mechanism is provided close (adjacent) to the workingspace area, where high machining precision is required, and thereforethe position locking mechanism can lock positions very accurately andprecisely based on the accurate and precise output of the positiondetecting mechanism to enable optimal exact spindle positioning duringthe machining operations.

In some preferred aspects, the position detecting mechanism may includean absolute encoder, in particular, wherein the absolute encoder maypreferably be arranged around the whole circumference of the front endportion of the turret body. Accordingly, very accurate and preciseposition detection is provided.

In some preferred aspects, the position locking mechanism may includeone or more hydraulic, pneumatic and/or electric brakes.

In some preferred aspects, the position locking mechanism may bearranged around the whole circumference of the front end portion of theturret body, e.g. by arranging brake mechanisms, particularly hydraulic,pneumatic and/or electric brakes, at circumferentially arrangedpositions.

In some preferred aspects, the machine frame may include a back frameportion rotatably supporting the back end portion of the turret bodyand/or a front frame portion rotatably supporting the front end portionof the turret body.

In some preferred aspects, a stator of the torque motor may be supportedby the back frame portion of the machine frame, and/or a rotor of thetorque motor may be arranged on the back end portion of the turret body.

In some preferred aspects, the position locking mechanism and/or aposition detecting mechanism may be mounted to the front frame portionof the machine frame.

In some preferred aspects, a space may be provided between the backframe portion and the front end portion.

In some preferred aspects, the turret body has, preferably for eachworkpiece spindle, a longitudinally extending groove portion forreceiving the workpiece spindle, the grooves preferably opening to thespace provided between the back frame portion and the front end portion.

In some preferred aspects, the turret body supports, preferably for eachworkpiece spindle, a slide being guided on longitudinal slides extendinglongitudinally with respect to the turret body and/or being arranged onan outer side of the turret body adjacent to the respective groove.

In some preferred aspects, the turret body may support, preferably foreach workpiece spindle, a drive mechanism for driving a longitudinallinear movement of the respective slide of the respective workpiecespindle.

In some preferred aspects, the drive mechanism may be arranged on afront end portion of the turret body and/or on a back end portion of theturret body, and/or a housing of the drive mechanism may extend radiallywith respect to the turret body into the space provided between the backframe portion and the front end portion.

In some preferred aspects, the turret body may be rotatably supported bytwo bearings, one bearing being preferably arranged on the back frameportion of the machine frame and another bearing being preferablyarranged on the front frame portion of the machine frame.

In some preferred aspects, a safety brake system may be arranged on theback frame portion of the machine frame, wherein, exemplarily, thesafety brake system may be including one or more electrically,pneumatically and/or hydraulically actuated brakes configured to brake arotational movement of the turret body, wherein in particular the safetybrake system may include one or more normally closed brakes being biasedinto a closing state by a biasing mechanism.

In some preferred aspects, a controller may be provided for controllinga machining of one or more workpieces received at the plurality ofworkpiece spindles, when the workpiece spindles are positioned atrespective machining positions.

In some preferred aspects, the controller may be further configured tocontrol the torque motor for controlling a rotational movement of theturret body for indexing the workpiece spindles between the respectivemachining positions and/or to control the position locking mechanism forlocking the position of the workpiece spindles in the machiningpositions during the machining of the one or more workpieces.

In some preferred aspects, the controller may be configured to cut acontrol current of a control signal to the torque motor after a drivenrotation of the turret body between the respective machining positionsand to actuate the locking position locking mechanism before controllingthe machining of the one or more workpieces; and/or the controller maybe configured to loosen the locked position locking mechanism and toactivate a control current of a control signal to the torque motor fordriving a rotation of the turret body to the next respective machiningpositions after machining of the one or more workpieces at the currentmachining positions.

In addition or alternative to the above, independently or separately,the present invention further proposes a bar loader (or a combination ofa machine tool with a bar loader, wherein the machine tool may be asingle-spindle, double-spindle or multi-spindle lathe or turningmachine). The bar loader may be configured to supply elongatedworkpieces, e.g. bars, from the rear side of the machine tool into therespective workpiece spindles of the one or more workpiece spindles ofthe machine tool. A main aspect of such bar loader may be that a barloader guiding system is provided that includes three portions,including a fixed guide portion, a slidable middle guide portion and aslidable end guide portion. The slidable portions being arranged to haveindividual guides for each associated spindle which are respectivelyslidable into a direction of a spindle axis of its respective associatedworkpiece spindle. Such aspects may be provided for single-spindle,double-spindle or multi-spindle lathe or turning machines, in case ofmulti-spindle machines with or without rotary turret body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 exemplarily illustrates a schematic perspective view of amulti-spindle turning machine according to an exemplary embodiment;

FIGS. 2A and 2B exemplarily illustrate schematic perspective views of atool post assembly of the multi-spindle turning machine of FIG. 1;

FIGS. 3A and 3B exemplarily illustrate schematic perspective views oftool posts of the multi-spindle turning machine of FIG. 1;

FIGS. 4A and 4B exemplarily illustrate schematic perspective views of atool post system of the multi-spindle turning machine of FIG. 1;

FIG. 5 exemplarily illustrates a schematic perspective view of a chipconveyor for use at the multi-spindle turning machine of FIG. 1;

FIGS. 6A and 6B exemplary illustrate schematic perspective views of amulti-spindle turning machine according to another exemplary embodiment;

FIGS. 7A and 7B exemplarily illustrate schematic perspective views of adrum of the multi-spindle turning machines of FIGS. 1, 6A and 6B;

FIGS. 8A to 8C exemplary illustrate schematic perspective views of amulti-spindle turning machine according to yet another exemplaryembodiment;

FIG. 9 exemplary illustrates a schematic perspective view of amulti-spindle turning machine according to yet another exemplaryembodiment;

FIGS. 10A to 10D exemplary illustrate schematic perspective views of amulti-spindle turning machine according to yet another exemplaryembodiment;

FIGS. 11A and 11B exemplary illustrate schematic perspective views of acounter-spindle assembly of the multi-spindle turning machines accordingto FIGS. 10A to 10D;

FIG. 12 exemplary illustrates a schematic perspective view of amulti-spindle turning machine according to yet another exemplaryembodiment;

FIGS. 13A to 13C exemplary illustrate schematic perspective views of abar loader for use at a multi-spindle turning machine and of partsthereof;

FIGS. 14A and 14B exemplary illustrate schematic perspective views of amachine frame for use at a multi-spindle turning machine according toyet another exemplary embodiment;

FIGS. 15A and 15B exemplarily illustrate schematic perspective views ofa drum of the multi-spindle turning machine frame of FIGS. 14A and 14B;

FIGS. 16A to 16C exemplarily illustrate schematic views of a drum of themulti-spindle turning machine frame and detail views thereof forillustrating a drive mechanism thereof; and

FIG. 17 exemplary illustrates a schematic perspective view of anemergency brake system at a multi-spindle turning machine according toyet another exemplary embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS AND DESCRIPTION OF EXEMPLARYEMBODIMENTS

In the following, preferred aspects and embodiments will be described inmore detail with reference to the accompanying figures. Same or similarfeatures in different drawings and embodiments are referred to bysimilar reference numerals. It is to be understood that the detaileddescription below relating to various preferred aspects and preferredembodiments are not to be meant as limiting the scope of the presentinvention.

FIG. 1 exemplarily illustrates a schematic perspective view of amulti-spindle turning machine 100 according to an exemplary embodiment.

The multi-spindle turning machine 100 of FIG. 1 comprises a machineframe 10 which includes a machine bed 11, a first machine frame upright12 (front frame portion) and a second machine frame upright 13 (backframe portion), wherein the first machine frame upright 12 and thesecond machine frame upright 13 are arranged on the machine bed 11.

A turret body 20 (spindle drum) is rotatably supported by the firstmachine frame upright 12 and the second machine frame upright 13 of themachine frame 10 of the multi-spindle turning machine 100. The turretbody 20 supports a plurality of workpiece spindles 30, exemplarilyarranged such that a respective spindle axis of the workpiece spindles30 is arranged in parallel with the rotational axis (longitudinal axis)of the turret body 20. Specifically, the workpiece spindles 30 areexemplarily arranged around the rotational axis (longitudinal axis) ofthe turret body 20, exemplarily with equiangular distance.

The turret body 20 is rotatably supported by each of the first andsecond machine frame uprights 12 and 13, and a free space is providedbetween the first and second machine frame uprights 12 and 13, so thatexemplarily the turret body 20 is only supported by the two machineframe uprights 12 and 13. Specifically, exemplarily a front end portionof the turret body 20 is rotatably supported by the first machine frameupright 12 (front frame portion) and a back end portion of the turretbody 20 is rotatably supported by the second machine frame upright 13(back frame portion).

In FIG. 1, the turret body 20 exemplarily carries six workpiece spindles30, but the invention is not limited to configurations with sixworkpiece spindles 30 arranged on the turret body 20, but the number ofspindles can be also less or more than six, e.g. a turret body carryingfour, five, seven, eight or more workpiece spindles. Exemplarily, forsix workpiece spindles 30, the equiangular distance between therespective adjacent workpiece spindles is ⅙ of 360°, i.e. exemplarily60°.

Further exemplarily, the first machine frame upright 12 (front frameportion) supports, for each of the workpiece spindles 30, a respectivetool post assembly 40 for carrying tools for processing/machiningworkpieces received at the respective workpiece spindles 30.Accordingly, in the present example, the first machine frame upright 12(front frame portion) supports six tool post assemblies 40, exemplarilyat the similar equiangular distance between adjacent tool postassemblies as the equiangular distance between adjacent workpiecespindles 30.

By such configuration, in a machining position of the turret body, eachof the tool post assemblies 40 is positioned so as to be enabled toprocess a workpiece held by the currently associated workpiece spindle30, and by indexing (rotating) the turret body 20, each of the workpiecespindles 30 can be moved to the next position of the next tool postassembly 40. Accordingly, the turret body 20 is configured toindex/rotate the workpiece spindles 40 between the multiple machiningpositions of the respective tool post assemblies 40. Such rotation(indexing) of the turret body 20 can be made in clockwise and/oranti-clockwise direction.

Regarding the movement kinematics of the multi-spindle turning machine100, exemplarily, the one or more tools held by each of the tool postassemblies 40 can exemplarily be moved relative to the workpiecereceived at a respective workpiece spindle 30 in three translationaldirections (three linear degrees of freedom). Exemplarily, this isachieved in that each workpiece spindle 30 is moveable in a longitudinaldirection which is axially arranged with respect to the respectivespindle axis (referred to as “Z-direction”; Z-axis), and in that eachtool post assembly 40 can be moved independently in two lineardirections which are exemplarily perpendicular to each other andperpendicular to the longitudinal direction (Z-direction). Suchdirections are exemplarily referred to as “X-direction” (X axis) and“Y-direction” (Y axis).

Exemplarily, for each tool post assembly 40 the respective X-directionis arranged radially with respect to the rotational axis of the turretbody 20 (i.e. the respective tool post assembly 40 can be moved in theX-direction perpendicular to and radially with respect to the rotationalaxis of the turret body 20), i.e. exemplarily perpendicular to theZ-direction of the respective workpiece spindle 30.

Exemplarily, for each tool post assembly 40 the respective Y-directionis arranged tangentially with respect to the rotational axis of theturret body 20 (i.e. the respective tool post assembly 40 can be movedin the Y-direction perpendicular to and tangentially with respect to therotational axis of the turret body 20), i.e. exemplarily preferablyperpendicular to the Z-direction of the respective workpiece spindle 30and perpendicular to the respective X-direction of said respective toolpost assembly 40.

On the side of the first machine frame upright 12 (front frame portion)opposite to the second machine frame upright 13 (back frame portion), aworkspace is provided, on which side thereof the tool post assemblies 40are provided on the first machine frame upright 12.

Below the tool post assemblies 40, exemplarily, a chip fall opening isprovided in the machine bed 11 of the machine frame 10, and a conveyoropening 11A is provided in the machine bed 11 of the machine frame 10 ona front side thereof, and the conveyor opening 11A is provided to inserta chip conveyor (see exemplary embodiments below). An advantage is thatchips being created by the machining processes of machining workpiecesreceived at the workpiece spindles 30 by tools held by the tool postassemblies 40 can fall freely downwards from the spindle positions tofall through the chip fall opening into a chip collector portion of achip conveyor inserted through the conveyor opening 11A.

FIGS. 2A and 2B exemplarily illustrate schematic perspective views of atool post assembly 40 of the multi-spindle turning machine of FIG. 1.

Exemplarily, each of the tool post assemblies 40 of the multi-spindleturning machine of FIG. 1 are configured similarly, only that they aremounted to the first machine frame upright 12 (front frame portion) onthe face side facing the workspace such that the respective X- andY-axes, which exemplarily are arranged perpendicularly with respect toeach other, are arranged depending on the longitudinal axis of theturret body, e.g. in that the plane spanned by the respective X- andY-axes is arranged perpendicular to the longitudinal axis of the turretbody 20 (i.e. that each of the respective X- and Y-axes is arrangedperpendicular to the longitudinal axis of the turret body 20), and inthat the respective X-axis is arranged radially with respect to thelongitudinal axis (rotational axis) of the turret body 20.

For providing the X- and Y-axes, the tool post assembly 40 exemplarilycomprises a cross slide assembly including a first slide 45 (X-slide)movable in the X-direction and a second slide 47 (Y-slide) movable inthe Y-direction, wherein the first slide 45 (X-slide) is arranged on thesecond slide 47 (Y-slide) as exemplarily shown in FIGS. 2A and 2B.

The tool post assemblies 40 further exemplarily comprise respectivedrives 46 and 48, wherein the drive 46 (e.g. drive motor) is configuredto drive the linear movement of the first slide 45 (X-slide) into theX-direction and the drive 48 (e.g. drive motor) is configured to drivethe linear movement of the second slide 47 (Y-slide) into theY-direction.

The X- and Y-direction movements can be independently driven and bysimultaneously driving the X- and Y-direction movements, the tool postcan be moved in any direction within the plane of the X- andY-directions, perpendicularly to the longitudinal axis of the turretbody 20 and perpendicular to the respective spindle axis of a respectiveworkpiece spindle 30.

The guide elements 49, along which guides of the second slide 47(Y-slide) are guided, are mountable to the first machine frame upright12 (front frame portion) at the respective positions as shown in FIG. 1,for example.

Exemplarily, each of the tool post assemblies 40 of the multi-spindleturning machine of FIG. 1, as exemplarily shown in FIGS. 2A and 2B,comprises a tool post 41 which has a plurality (exemplarily three) toolreceiving openings 41A, 41B and 41C for receiving tools. Exemplarily,the tool receiving openings 41A, 41B and 41C are arranged adjacent toeach other and are arranged along the Y-direction.

This has the advantage that, by moving the tool post 41 into theY-direction, the respective tool, which actually engages the workpiecereceived at the respective workpiece spindle, can be changed among thetools received in the tool receiving openings 41A, 41B and 41C.Accordingly, without actually inserting a new tool into the tool post41, the tools engaging into the machining operation at a respectiveworkpiece spindle 30 can be quickly, efficiently and reliably changed bymerely moving the tool post 41 into the Y-direction.

Also, the tool post assembly 40 is configured to drive tools received inthe tool receiving openings 41A, 41B and 41C (so-called live tools) byway of the optional drive mechanism including the drive 43 (e.g. a drivemotor in a drive housing) and the gearbox 42. Specifically, the gearbox42 may include a gear mechanism, which may be configured to allow forone or more gear changes for different gear ratios, and the gearmechanism may be driven by the drive 43 so as to drive one or more ofthe tools received in the tool receiving openings 41A, 41B and 41C.

For example, the gearbox may be configured to include a gear mechanismwhich may be set to (or switched between) one or more gear settings,which may be provided for driving one or more of the tools received inthe tool receiving openings 41A, 41B and 41C at high revolution speedsand/or high torque, e.g. depending on the intended machining conditionand/or depending on the used live tool.

FIGS. 3A and 3B exemplarily illustrate schematic perspective views oftool posts of the multi-spindle turning machine of FIG. 1.

Exemplarily, FIG. 3A illustrates a tool post 41 with the mountingportion 44 on which the drive 43 (exemplarily including a housing and adrive motor being arranged in the housing) and the gearbox 42 aremounted, and FIG. 3B illustrates a tool post 41 with the mountingportion 44 from which the drive 43 and the gearbox 42 are detached.

That is, the drive 43 (e.g. drive motor) and the gearbox 42 may beoptional in the sense that the tool post assembly 40 may be configuredto detachably mount the drive unit including the drive 43 and thegearbox 42 to the tool post 41, e.g., on a mounting portion 44 which isexemplarily arranged on the first slide 45 (X-slide) and whichexemplarily supports the tool post 41. Accordingly, if no live tools areintended to be used or required, the drive unit including the drive 43and the gearbox 42 may be demounted or detached from the tool post 41,e.g. if only fixed tools (e.g. fixed cutter blades) are inserted to thetool receiving openings 41A, 41B and 41C.

Exemplarily, in FIGS. 3A and 3B, the drive 43 and the gearbox 42 may bemechanically fixed to the mounting portion 44, e.g., by way of screws orthe like. In other exemplary embodiments, the drive 43 and the gearbox42 may be mechanically fixed to the tool post 41 directly. In yetfurther exemplary embodiments, the drive 43 and the gearbox 42 may bemounted to the mounting portion 44 and/or the tool post 41 and lockedmechanically and/or by electric, pneumatic and/or hydraulic lockingmechanisms.

FIGS. 4A and 4B exemplarily illustrate schematic perspective views of atool post system of the multi-spindle turning machine of FIG. 1.Exemplarily, according to FIGS. 4A and 4B, the tool post system has aconfiguration that the tool receiving openings 41A, 41B and 41C of thetool post 41 are adapted to receive detachable, replaceable andinterchangeable tool holder cartridges TC which are configured to holdrespective tools.

For example, FIG. 4A exemplarily illustrates a plurality ofinterchangeable tool holder cartridges TC, each of which can be insertedinto the tool receiving openings 41A, 41B and 41C of the tool post 41which may, depending on the intended machining operations and the usedtools, be optionally augmented with the optionally added drive 43 andthe gearbox 42 to be detachably mounted to the mounting portion 44(and/or the tool post 41), as exemplarily described above.

The plural tool holder cartridges TC, having the interchangeablecartridge design to be fitted into the fitting tool receiving openings41A, 41B and 41C (as cartridge-receiving openings), are adapted to holda variety of different tools such as fixed tools FT in FIG. 4A (e.g.fixed blades, fixed cutters, etc.) or live tools (i.e. drivable tools)such as boring tools, milling tools, drill bits, etc. For such livetools, some of the cartridges TC are adapted to hold axially arrangedlive tools ALT which are rotationally driven about a tool axis arrangedaxially with a longitudinal axis of the respective cartridge TC, thelongitudinal axis of the respective cartridge TC being the axis of theinsertion direction into the tool receiving openings 41A, 41B and 41C(as cartridge-receiving openings).

Exemplarily, some of the cartridges TC are adapted to holdvertically/perpendicularly arranged live tools PLT which arerotationally driven about a tool axis arranged perpendicularly withrespect to the longitudinal axis of the respective cartridge TC. Furtherexemplarily, one of the cartridges TC is adapted to hold avertically/perpendicularly arranged double live tool DPLT with two toolswhich are rotationally driven about a tool axis arranged perpendicularlywith respect to the longitudinal axis of the respective cartridge TC.

Accordingly, while each of the plural tool cartridges TC has the sameinterface fitting end portion to fit into the tool receiving openings41A, 41B and 41C (as cartridge-receiving openings), a front portion ofthe plural tool cartridges TC may be adapted according to differenttypes of tools, e.g. to receive/hold one or more fixed tools FT, toreceive/hold an axially drivable tool ALT, to receive/hold aperpendicularly drivable tool PLT (perpendicular live tool) or even toreceive/hold one or more drivable tools, such as axially drivable doubletools and perpendicularly drivable double tools, etc.

Whenever it is intended to use at least one live tool (drivable tool) atthe tool post 41, the optionally available drive unit including the gearbox 42 and the drive 43 can be detachably mounted as exemplarilyillustrated in FIG. 4A.

Exemplarily, FIG. 4B illustrates such situation in which a toolcartridge TC holding an axially drivable tool ALT (axial live tool) isexemplarily inserted into the tool receiving opening 41B of the toolpost 41, and, for driving the axially drivable tool ALT, the gear box 42and the drive 43 are exemplarily mounted to the mounting portion 44(and/or to the tool post 41).

For fixedly holding the tool cartridges in the tool receiving openings41A, 41B and 41C (as cartridge-receiving openings), the tool post 41 maybe configured to enable mechanical fixing or locking the receivedcartridges TC, e.g. by means of screws and/or a clamping or othermechanical locking mechanism, e.g. also including quick-acting fastenersor quick clamps.

In further exemplary embodiments, in alternative or in addition, thetool post 41 may be equipped with automatically actuatedlocking/unlocking mechanisms to automatically lock/unlock toolcartridges TC received in the tool receiving openings 41A, 41B and 41C(as cartridge-receiving openings) of the tool post 41. Specifically,such automatically actuated locking/unlocking mechanisms may beincluding mechanical, pneumatic, hydraulic and/or electriclocking/unlocking mechanisms. Accordingly, locking/unlocking toolcartridges TC received in the tool receiving openings 41A, 41B and 41C(as cartridge-receiving openings) of the tool post 41 may be actuatedautomatically by way of mechanical, pneumatic, hydraulic and/or electricactuators.

This would exemplarily advantageously allow for a possibility of anautomatic tool change function to be provided at the multi-spindleturning machine. While automatic tool change mechanisms are well knownin the field of machine tools with tool-carrying spindles, such asmilling machines or milling machining centers, efficient and reliableautomatic tool change mechanisms are not yet realized in the field ofturning machines/lathes, specifically for multi-spindle turning machine,and therefore such automatic tool change system at a turning machine,such as a multi-spindle turning machine, is highly beneficial andsignificantly improves the versatility of the respective turningmachine.

For example, in case of equipping a multiple-spindle turning machinewith handing robots, such robots could be used to handle workpieces atthe workpiece spindles (e.g. for workpiece removal after the machiningprocess) and/or tools to be removed from or inserted to the tool post 41of one of the tool post assemblies 40 (see below exemplary embodiments).

Even without automatically actuated locking/unlocking mechanisms, thehighly flexible and efficiently usable tool cartridge system with pluralinterchangeable tool holding cartridges fitted to the tool receivingopenings 41A, 41B, and 41C of the tool post 41 makes it advantageouslypossible to efficiently, more quickly and accurately enable toolexchanges, be it made manually, automatically or semi-automatically, atthe turning machine, such as the multi-spindle turning machine.

FIG. 5 exemplarily illustrates a schematic perspective view of a chipconveyor 200 for use at the multi-spindle turning machine 100 of FIG. 1.

Exemplarily, the chip conveyor 200 (chip conveyor apparatus) includes achip collector portion 210 which is opened to the upper side. The chipcollector portion 210 may be inserted into the chip conveyor opening 11Aof the machine bed 11 of the machine frame 10 of the multi-spindleturning machine, e.g. as illustrated in FIG. 1. Accordingly, wheninserted in the conveyor opening 11A, the chips created by the machiningoperations of workpieces received at the workpiece spindles 30 beingmachined by the tools of the tool post assemblies 40 will advantageouslybe enabled to fall straight down into the chip collector portion 210 ofthe chip conveyor 200.

The chip conveyor 200 exemplarily further includes an inclined conveyingportion 230 which internally has a conveyor system for conveying chipscollected in the chip collector portion 210 upwards towards the chipoutput portion 240, which has a lower opening to output conveyed chips,e.g. into a collector container that may be placed under the chip outputportion 240. For driving the conveyor system, the chip conveyor 200further includes a conveyor drive 220.

FIGS. 6A and 6B exemplary illustrate schematic perspective views of amulti-spindle turning machine 100 according to another exemplaryembodiment.

The principle configuration of the multi-spindle turning machine 100 ofFIGS. 6A and 6B is similar to the exemplary embodiments discussed abovein connection with FIG. 1. However, the chip conveyor 200 is exemplarilyinserted into the conveyor opening 11A of the machine bed 11 of themachine frame 10.

Further exemplarily, the multi-spindle turning machine 100 of FIGS. 6Aand 6B is exemplarily equipped with two automatically controlled robots301 and 302 (exemplarily, six-axis robots). For example, the first robot301 is mounted to an upper portion of the workspace facing side of thefirst machine frame upright 12 (front frame portion) of the machineframe 10. The second robot 302 is exemplarily mounted to a portion ofthe machine bed 11 of the machine frame 10 opposite to the first machineframe upright 12 with respect to the workspace (i.e. a region above thechip fall opening formed in the machine bed 11 of the machine frame 10).

Exemplarily, both of the robots 301 and 302 include grippers G adaptedto pick up workpieces from the workpiece spindles 30 (e.g. to removeworkpieces after completion of the machining process) and/or adapted topick up (and/or insert) tool cartridges TC at the tool posts 41 of thetool post assemblies 41, e.g. for automated tool exchanges. Theexemplary embodiments are not limited to configurations having tworobots but also only one of the robots 301 or 302 may be provided, oradditional robots may be provided in yet further exemplary embodiments.

FIGS. 7A and 7B exemplarily illustrate schematic perspective views of adrum (turret body 20) of the multi-spindle turning machines 100 of FIGS.1, 6A and 6B.

Exemplarily, only the turret body 20 is shown with one exemplary spindleslide mechanism of a respective workpiece spindle 30, wherein thespindle slide mechanism includes a spindle slide 31 which supports aspindle body 32 which includes an integrated spindle drive (built-inspindle motor) and a actuated locking mechanism (e.g. a mechanically,hydraulically, pneumatically and/or electrically actuated lockingmechanism) to automatically lock received workpieces (such as e.g. bars)in the spindle to rotatively drive the received and locked workpieces bythe spindle drive.

The turret body 20 exemplarily includes a front end portion 22 and aback end portion 21 which are the portions respectively supportedrotatably by the front frame portion 12 and the back frame portion 13 ofthe machine frame 10. The front end portion 22 of the turret body 20includes openings 25 to receive the workpiece spindles 30 (specificallythe front portions thereof), and the back end portion 21 of the turretbody 20 includes openings 26 through which each of the spindles 30 maybe supplied with workpieces (such as e.g. bars) from a backside of themulti-spindle turning machine 100. This has the advantage thatworkpieces, such as e.g. long bars, do not need to be inserted from aworkspace side but may be supplied/inserted by a bar loader or barfeeder from a backside of the machine, where more space may beavailable. Then, workpieces only may need to be removed after machiningfrom a front side at the working space, when such workpieces may beeasier to be handled, e.g. automatically by external handling robots oradditionally integrated robots such as e.g. in FIGS. 6A and 6B.

However, as can be seen from FIGS. 7A and 7B, exemplarily, the turretbody 20 does not have through holes from the front side to the backsideof the turret body 20 for each of the spindles 30, as typically knownfrom known multi-spindle turning machines, but the turret body 20 has,for each of the workpiece spindles 20, a respective longitudinal groove23 extending longitudinally (Z-direction/longitudinal direction of theturret body 20) from the front end portion 22 of the turret body 20 tothe back end portion 21 of the turret body 20. The longitudinal grooves23 are exemplarily opened to the outer circumferential side of theturret body 20 so as to open to the space between the front frameportion 12 and the back frame portion 13 of the machine frame 10.

Exemplarily, the turret body 20 has, between each pair of adjacentgrooves 23, a respective ledge portion 24 extending longitudinally(Z-direction/longitudinal direction of the turret body 20) from thefront end portion 22 of the turret body 20 to the back end portion 21 ofthe turret body 20. Exemplarily, the number of grooves 23 is the same asthe number of longitudinal ledge portions 24.

The spindle body 32 of the workpiece spindle 30 is exemplarily guided inthe respective longitudinal groove 23 and supported by the spindle slide31 which is arranged at an outer circumferential side of the turret body20. Specifically, each spindle slide 31 is exemplarily guided, withguide elements 35, on the longitudinal ledge portions 24 formed on thesides of the respective grooves 23.

Such configuration has the advantage that the slides 31 and their drivemechanisms may be provided outside on an outer circumferential side ofthe turret body 20, so that the turret body 20 can be made efficientlycompact and light-weight, since the radiating profile of the turret body20 having the groove-ledge arrangement gives very high stability andstiffness even at relatively low ledge thickness, and the spindles canbe arranged more compactly since the spindle slides and their drivemechanisms can be arranged circumferentially outside of the turret body20, efficiently using the space between the front and back frameportions 12 and 13, and the size of the slides and their drive mechanismdoes not need to be compactified, even though the turret body 20 is verycompact.

Exemplarily, the slide drive mechanism includes a thread shaft 34 drivenby a drive 33 (drive motor). In FIGS. 7A and 7B, the drive 33 is notmounted to the spindle slide 31 but may itself be mounted to a mountstructure of (or attached to) the back portion the turret body 20.

When rotatively driving the thread shaft 34 by way of the drive 33, therespective spindle slide 31 is driven in the longitudinal direction(Z-direction, axially with respect to the respective spindle axis) alongthe guiding ledges 24 so as to move the spindle body 32 of therespective workpiece spindle 30 in the longitudinal Z-direction (e.g.towards or away from the workspace) within the respective longitudinalgroove 23.

FIGS. 8A to 8C exemplary illustrate schematic perspective views of amulti-spindle turning machine 100 according to yet another exemplaryembodiment. The principle configuration of the multi-spindle turningmachine 100 of FIGS. 8A to 8C is similar to the exemplary embodimentsdiscussed above in connection with FIGS. 1, 6A and 6B.

Exemplarily, the FIG. 8A illustrates schematically a machine housing 110of the multi-spindle turning machine 100. FIGS. 8B and 8C illustrate themulti-spindle turning machine 100 without housing 110. Such housing mayalso be provided for other described exemplary embodiments above andbelow.

Furthermore, the multi-spindle turning machine 100 of FIGS. 8A to 8C isexemplarily equipped with a chip conveyor 200 as exemplarily shown inFIG. 5, similar as the machine tool of FIGS. 6A and 6B.

In addition, a bar loader 300 is exemplarily shown in FIG. 8A, beingarranged on the rear side of the multi-spindle turning machine 100facing the back frame portion 13 of the machine frame 10, which barloader 300 is configured to supply elongated workpieces, e.g. bars (e.g.bars with a round or circular cross section or bars with an angled crosssection such as e.g. a hexagonal cross section), from the rear side intothe respective workpiece spindles 30 through the holes 26 formed in theback end portion 21 of the turret body 20 (see e.g. FIG. 8C). Such barloader 300 may be used in other exemplary embodiments described aboveand below.

In addition, different to previously described exemplary embodiments,the multi-spindle turning machine 100 of FIGS. 8A to 8C exemplarilyincludes a pick-up spindle mechanism 50 which is mounted on a beamportion 14 of the machine frame 10 which is exemplarily arranged on theupper side of the front frame portion 12 and which exemplarily extendsfrom the upper side of the front frame portion 12 into the workingspace.

The pick-up spindle mechanism 50 with its pick-up spindle 51 isexemplarily arranged in a hanging position being mounted to the beamportion 14 of the machine frame 10 from below and hanging from the beamportion 14 of the machine frame 10. This has the advantage that thepickup-spindle mechanism does not obstruct the free space of chip fallbelow the spindles (including the pick-up spindle).

The pick-up spindle mechanism 50 includes a support portion 53 which ismounted, in the hanging position, to the bottom side of the beam portion14 of the machine frame 10, exemplarily by way of guide elements 54which are guided along a longitudinal direction (Z-direction) in guidesarranged on the bottom side of the beam portion 14. The pick-up spindlemechanism 50 exemplarily further includes a drive 56 (drive motor) todrive movement of the support portion 53 (pickup-spindle slide) in thelongitudinal direction (Z-direction) towards and away from the opposingworkpiece spindles 30.

The support portion 53 supports (holds) the pickup-spindle 51 which isdriven by another drive 52 (drive motor), e.g. via a driving belt 55.The pickup-spindle 51 and the drive 52 are arranged on (mounted to) thesupport portion 53, and by moving the support portion 53 in thelongitudinal direction (Z-direction), the pickup-spindle 51 can be movedtowards and away from the opposing workpiece spindles 30 for picking upa workpiece received at one of the workpiece spindles 30 for rearmachining purposes.

For such rear machining processing, the pickup-spindle may rotativelydrive the picked up workpiece, which has a rear side, which waspreviously received in the respective workpiece spindle 30, now openlyfacing the workspace for being machined on said rear side, and said rearside of the workpiece may be machined by using the tools of the toolpost 40 associated with the respective workpiece spindle 30 opposite ofthe pickup spindle 51 and/or by way of additional tools (fixed tools ordriven tools, i.e. live tools) which may be mounted to or arranged onthe support portion 53 or on tool post assemblies mounted to or arrangedon the support portion 53.

The configuration advantageously allows for a very efficient and compactconfiguration allowing for additional rear machining of workpieces withoptimized chip fall conditions.

FIG. 9 exemplary illustrates a schematic perspective view of amulti-spindle turning machine 100 according to yet another exemplaryembodiment, similar to the exemplary embodiments of FIGS. 8A to 8C.

In addition, similar to FIGS. 6A and 6B, the multi-spindle turningmachine 100 of FIG. 9 is exemplarily equipped with a robot 302(exemplarily a six-axis robot). The robot 302 is exemplarily mounted toa portion of the machine bed 11 of the machine frame 10 opposite to thefirst machine frame upright 12 with respect to the workspace (i.e. aregion above the chip fall opening formed in the machine bed 11 of themachine frame 10).

Exemplarily, the robot 302 includes a gripper G adapted to pick upworkpieces from the workpiece spindles 30 (e.g. to remove workpiecesafter completion of the machining process), to pick up workpieces fromthe pick-up spindle 53 (as exemplarily shown in FIG. 9) and/or adaptedto pick up (and/or insert) tool cartridges TC at the tool posts 41 ofthe tool post assemblies 41, e.g. for automated tool exchanges. Theexemplary embodiments are not limited to configurations having one robotbut also two or more robots may be provided in yet further exemplaryembodiments.

FIGS. 10A to 10D exemplary illustrate schematic perspective views of amulti-spindle turning machine 100 according to yet another exemplaryembodiment.

Furthermore, the multi-spindle turning machine 100 of FIGS. 10A to 10Dis exemplarily equipped with a chip conveyor 200 as exemplarily shown inFIG. 5, similar as the machine tool of FIGS. 6A and 6B and FIGS. 8A to9.

In addition, a bar loader 300 is exemplarily shown in FIG. 10A (similarto FIG. 8A), being arranged on the rear side of the multi-spindleturning machine 100 facing the back frame portion 13 of the machineframe 10, which bar loader 300 is configured to supply elongatedworkpieces, e.g. bars, from the rear side into the respective workpiecespindles 30 through the holes 26 formed in the back end portion 21 ofthe turret body 20. Such bar loader 300 may be used in other exemplaryembodiments described above and below.

In addition, different to previously described exemplary embodiments,the multi-spindle turning machine 100 of FIGS. 10A to 10D exemplarilyincludes a counter-spindle mechanism 60 which is mounted on a beamportion 14 of the machine frame 10 which is exemplarily arranged betweenthe upper side of the front frame portion 12 and an upper side ofanother (third) machine frame upright 15 (third machine frame portion)arranged opposite of the front frame portion 12 with respect to theworkspace (opposite of the workpiece spindles 30), and which beamportion 14 exemplarily extends from the upper side of the front frameportion 12 into the working space.

The counter-spindle mechanism 60 exemplarily comprises twocounter-spindles 61, however, other exemplary embodiments with one ormore than two counter-spindles are also possible in yet furtherexemplary embodiments.

The counter-spindle mechanism 60 with its counter-spindles 61 isexemplarily arranged in a hanging position being mounted to the beamportion 14 of the machine frame 10 from below and hanging from the beamportion 14 of the machine frame 10. This has the advantage that thecounter-spindle mechanism does not obstruct the free space of chip fallbelow the spindles (including the counter-spindles). Embodiments withtwo counter-spindles have an advantage that both of double cyclemachining operations and double rear machining operations becomepossible (for double cycle machining operations and double rearmachining operations, please see e.g. EP 2 163 334 B2).

Furthermore, as exemplarily shown in FIG. 10A, e.g. for (double) rearmachining operations performed on workpieces received at thecounter-spindles 61, the multi-spindle turning machine 100 exemplarilyfurther comprises two additional tool posts 71 and 72, which areexemplarily arranged in a hanging position mounted to the bottom side ofthe beam portion 14 between the counter-spindles 61 of thecounter-spindle mechanism 60 and the workpiece spindles 30. Each of thetool posts 71 and 72 is adapted to hold one or more tools (includingfixed tools and/or drivable tools, e.g. live tools).

The exemplary embodiment exemplarily comprises two additional tool posts71 and 72 for rear machining purposes of workpieces received at thecounter-spindles 61, however, other exemplary embodiments with one ormore than two additional tool posts are also possible in yet furtherexemplary embodiments.

FIGS. 11A and 11B exemplary illustrate schematic perspective views of acounter-spindle assembly of the counter-spindle mechanism 60 of themulti-spindle turning machines according to FIGS. 10A to 10D.

For each counter-spindle 61, the counter-spindle mechanism 60 includes arespective counter-spindle assembly which includes the respectivecounter-spindle 61 supported by a spindle slide 64 which is slidablysupported by a cross slide assembly including a first slide 63 and asecond slide 62. The first slide 63 is slidably supported on the secondslide 62, and the second slide 62 is slidably supported on the bottomside of the beam portion 14.

By movement of the respective second slide 62 with respect to the beamportion 14 along guides 67, exemplarily arranged on the bottom side ofthe beam portion 14 so as to extend into a longitudinal direction(Z-direction), by the drive 65 (drive motor), the respectivecounter-spindle 61 can be moved into the longitudinal direction(Z-direction) which is exemplarily arranged in parallel with respect tothe spindle axis of the respective counter-spindle 61 and the spindleaxes of the workpiece spindles 30. That is, by such movement in theZ-direction, i.e. towards or away from the opposing workpiece spindles30, a respective workpiece received at one of the workpiece spindles 30may be picked up by the respective counter-spindle 61 for rear machiningpurposes.

Furthermore, by movement of the respective first slide 63 with respectto the second slide 62 along guides 68, exemplarily arranged on thebottom side of the second slide 62 so as to extend into a horizontaldirection (X-direction) perpendicular to the longitudinal direction(Z-direction), by another drive (drive motor, not shown), the respectivecounter-spindle 61 can be moved into the horizontal direction(X-direction) perpendicularly with respect to spindle axis of therespective counter-spindle 61 and the spindle axes of the workpiecespindles 30.

Furthermore, by movement of the respective spindle slide 64 with respectto the first slide 63 along guides (not shown), exemplarily arranged onthe first slide 63 so as to extend into a vertical direction(Y-direction) perpendicular to the longitudinal direction (Z-direction),by another drive 66 (drive motor), the respective counter-spindle 61 canbe moved into the vertical direction (Y-direction) perpendicularly withrespect to spindle axis of the respective counter-spindle 61 and thespindle axes of the workpiece spindles 30.

By the above counter-spindle assemblies of the counter-spindle mechanism60, each of the counter-spindles can be moved independently in all threedirections X, Y and Z, and highly flexible and accurate rear machiningoperations become possible.

For rear machining processing, a respective counter-spindle 61(simultaneously with the other counter-spindle or asynchronously withthe other counter-spindle) may rotatively drive the picked up workpiece,which has a rear side, which was previously received in the respectiveworkpiece spindle 30, now openly facing the workspace for being machinedon said rear side, and said rear side of the workpiece may be machinedby way of additional tools (fixed tools or driven tools, i.e. livetools) which may be held by the tool post 71 and 72.

The configuration advantageously allows for a very efficient and compactconfiguration allowing for additional rear machining of workpieces withoptimized chip fall conditions, specifically since the chips may falldownwards to and through the chip opening 11B formed in the machine bed11 of the machine frame without being obstructed by the counter-spindlemechanism 60 or the tool posts 71 and 72.

Furthermore, the configuration having the beam portion 14 beingsupported on both sides, respectively by the upper portion of the frontframe portion 12 and the outer frame portion 15, has an advantage that ahigh stability and advantageous stiffness of the machine frame can beachieved.

FIG. 12 exemplary illustrates a schematic perspective view of amulti-spindle turning machine 100 according to yet another exemplaryembodiment, similar to the exemplary embodiments of FIGS. 10A to 10D.

In addition, similar to FIGS. 6A and 6B and 9, the multi-spindle turningmachine 100 of FIG. 12 is exemplarily equipped with a robot 302(exemplarily a six-axis robot). The robot 302 is exemplarily mounted toa portion of the machine bed 11 of the machine frame 10 opposite to thefirst machine frame upright 12 with respect to the workspace (i.e. aregion above the chip fall opening 11B formed in the machine bed 11 ofthe machine frame 10).

Exemplarily, the robot 302 includes a gripper G adapted to pick upworkpieces from the workpiece spindles 30 (e.g. to remove workpiecesafter completion of the machining process), to pick up workpieces fromthe counter-spindles 61 and/or adapted to pick up (and/or insert) toolcartridges TC at the tool posts 41 of the tool post assemblies 41, e.g.for automated tool exchanges, and/or even to pick up (and/or insert)tool cartridges TC at the tool posts 71 and 72 hanging from the beamportion 14 (not shown in FIG. 12). The exemplary embodiments are notlimited to configurations having one robot but also two or more robotsmay be provided in yet further exemplary embodiments.

FIGS. 13A to 13C exemplary illustrate schematic perspective views of abar loader 300 for use at a multi-spindle turning machine 100 and ofparts thereof. Such bar loader 300 may exemplarily be used at any of themachine tools of above or below exemplary embodiments.

FIG. 13A exemplary illustrates the bar loader 300 with a housing 310 anda stand 320. Through an opening on a side of the housing 310, the barloader includes a bar receiving portion 330 for receiving (beingsupplied) with unprocessed bars or other elongated workpieces to bemachined at the multi-spindle turning machine 100. Such elongatedworkpieces may have round profiles of various widths or other profiles.

On one side of the bar loader 300, a turret fixture body 340 extendslaterally from the bar loader 300. The turret fixture body 340 isrotatably supported around a longitudinal axis to be axially arrangedwith the rotational longitudinal axis of the turret body 20 of themulti-spindle turning machine 100. The turret fixture body 340 isconfigured to be fixed to the turret body 20 (e.g. by plural fixturerods) from a rear side of the multi-spindle turning machine 100 througha through hole of the back frame portion 13 (see e.g. FIG. 8C) so as torotate together with the turret body 20 about the axially arrangedlongitudinal axes thereof.

Specifically, the turret body 20 and the turret fixture body 340 areexemplarily configured to be rigidly fixed to each other to rotatetogether about the common longitudinal axis. Accordingly, exemplarilythe driven rotation of the guide system of the bar loader supported bythe turret fixture body 340 is performed by mechanical connection of theturret fixture body 340 with the rear side of the turret body 20 throughplural mechanical connections (e.g. by plural fixture rods) working onthe external diameter of a rear flange of the machine. This mechanicalconnection of the turret fixture body 340 with the rear side of theturret body 20 assures the proper angular synchronisms with the spindlesin the turret body 20 itself. Accordingly, the rotation of the barloader guide system and the turret fixture body 340 of the bar loader300 is exemplarily performed by the torque motor 80 described below.

FIG. 13B exemplarily illustrates the bar loader 300 of FIG. 13A withouthousing 310 having an inner guide system, which is exemplarily shown inFIG. 13C.

The bar loader guide system as a whole is, together with the turretfixture body 340, rotatably supported about the longitudinal axis of theturret fixture body 340 (longitudinal axis of the guide system), and theguide system includes a fixed guide portion 360, a slidable middle guideportion 350 and a slidable end guide portion 370, wherein each of thefixed guide portion 360, the slidable middle guide portion 350 and theslidable end guide portion 370 are, together, rotatably supported aboutthe longitudinal axis of the turret fixture body 340 (longitudinal axisof the guide system).

Accordingly, when the turret body 20 of the multi-spindle turningmachine 100 is rotated/indexed, the turret fixture body 340 of the barloader 300, being fixed to the turret body 20 of the multi-spindleturning machine 100, rotates in a synchronous manner together with theturret body 20 of the multi-spindle turning machine 100, and the guidesystem including the fixed guide portion 360, the slidable middle guideportion 350 and the slidable end guide portion 370 is driven to berotated together with the turret fixture body 340 of the bar loader 300and the turret body 20 about the common longitudinal axis.

Preferably, the control of the driven rotation of the guide system isthereby performed by driving rotation of the turret 20 by control fromthe numerical control apparatus (NC) and/or the programmable logiccontroller (PLC) of the multi-spindle turning machine 100. This has theadvantage that the control of the rotation of the turret body 20 and therotation of the guide system of the bar loader 300 is synchronouslycontrolled.

In addition, preferably, the numerical control system of themulti-spindle turning machine 100 (including the NC and/or the PLC) maybe communicably connected with the bar loader's control system accordingto a master/slave relationship. This has the advantage that thenumerical control apparatus (NC) and/or the PLC of the machine isenabled to manage directly plural or all of the functionalities of thebar loader (e.g. the machine is the “master”, and the bar loader is the“slave”). Functionalities of the bar loader system may include at leastone of: the selection and lifting of a new bar from a bar storage areainto the guide system of the bar loader, the introduction of a new barinto a bar loader channel of the guide system, pushing of the bar forfeeding new raw material for machining process (e.g. after receiving aspecific signal, exemplarily indicating that a spindle collet isopened), and handling of a bar remnant.

The fixed guide portion 360 of the bar loader 300 exemplarily has pluralfixed bar guide portions 361 arranged around the longitudinal axis, eachfixed bar guide portion 361 being provided for receiving a bar/elongatedworkpiece for a respective one of the workpiece spindles 30 of themulti-spindle turning machine 100 so that the number of fixed bar guideportions 361 is the same as the number of workpiece spindles 30 of themulti-spindle turning machine 100, at same angular distancescorresponding to the angular distances of the workpiece spindles 30 ofthe multi-spindle turning machine 100 arranged on the turret body 20.

The slidable middle guide portion 350 has plural slidable bar guideportions 351 arranged around the longitudinal axis, each slidable barguide portion 351 being provided for receiving a bar/elongated workpiecefor a respective one of the workpiece spindles 30 of the multi-spindleturning machine 100 so that the number of slidable bar guide portions351 is the same as the number of workpiece spindles 30 of themulti-spindle turning machine 100, at same angular distancescorresponding to the angular distances of the workpiece spindles 30 ofthe multi-spindle turning machine 100 arranged on the turret body 20.

Each slidable bar guide portion 351 of the slidable middle guide portion350 is associated with a respective fixed bar guide portion 361 of thefixed guide portion 360, and the respective slidable bar guide portion351 is axially arranged with its associated fixed bar guide portion 361in parallel with the longitudinal direction, so that the respectiveslidable bar guide portion 351 with its associated fixed bar guideportion 361 are configured to simultaneously receive a bar/elongatedworkpiece supplied through the bar receiving portion 330.

Accordingly, both of the slidable bar guide portion 351 with itsassociated fixed bar guide portion 361 can be actuated to laterally openfor laterally receiving the same bar/elongated workpiece suppliedthrough the bar receiving portion 330, and then to be actuated to belaterally closed for enclosing the bar and providing a longitudinallyextending guide channel for the respective received bar.

A feeding mechanism of the fixed guide portion 360 is configured to feedbars/elongated workpieces, received in the slidable bar guide portion351 with its associated fixed bar guide portion 361, in the longitudinaldirection towards the slidable end guide portion 370 and the turretfixture body 340.

The slidable end guide portion 370 has plural slidable bar guideportions 371 arranged around the longitudinal axis, each slidable barguide portion 371 being provided for receiving a bar/elongated workpiecefor a respective one of the workpiece spindles 30 of the multi-spindleturning machine 100 so that the number of slidable bar guide portions371 is the same as the number of workpiece spindles 30 of themulti-spindle turning machine 100, at same angular distancescorresponding to the angular distances of the workpiece spindles 30 ofthe multi-spindle turning machine 100 arranged on the turret body 20.

Each slidable bar guide portion 371 of the slidable end guide portion370 is associated with a respective slidable bar guide portion 351 ofthe slidable middle guide portion 370, and the respective slidable barguide portion 371 is axially arranged with its associated slidable barguide portion 351 in parallel with the longitudinal direction, so thatthe respective slidable bar guide portion 371 with its associatedrespective slidable bar guide portion 351 are configured tosimultaneously guide a bar/elongated workpiece, when the respectivebar/elongated workpiece is fed from the fixed guide portion 360 towardsthe slidable end guide portion 370 and the turret fixture body 340.

In addition, each slidable bar guide portion 371 of the slidable endguide portion 370 longitudinally extends though the turret fixture body340 of the bar loader 300, being fixed to the turret body 20 of themulti-spindle turning machine 100, so as to extend through the openings26 of the back end portion 21 of the turret body 20 of the multi-spindleturning machine 100, so that each slidable bar guide portion 371 may beconnected or fixed to a respective spindle body 32 of a respectiveworkpiece spindle 30, e.g. by one or more connection elements (e.g.connection rods or the like), preferably one or more per spindle, asexemplarily shown in FIGS. 13A and 13B (connection elements 380).

When the respective bar/elongated workpiece is fed through therespective slidable bar guide portion 371 to extend into the connectedspindle body 32 of a respective workpiece spindle 30, another optionalfeeding mechanism may be provided in the spindle body 32 of a respectiveworkpiece spindle 30, so that the slidable bar guide portions 351 and371 may be provided without another feeding mechanism, and the slidablebar guide portions 351 and 371 may preferably provide a guide channelproviding guiding support for long bars or other elongated workpieces.

Exemplarily, contrary to the fixed bar guide portion 361 of the fixedguide portion 360, each slidable bar guide portion 371 with itsrespective associated slidable bar guide portion 351 is exemplarilyconfigured to longitudinally slide together with the longitudinalmovement of the respective workpiece spindle 30 in the longitudinalZ-direction.

Specifically, since the workpiece spindles 30 are configured to bedriven independently from each other in the longitudinal Z-direction,each of the slidable bar guide portions 371 with its respectiveassociated slidable bar guide portion 351 is adapted to longitudinallyslide independent of the other slidable bar guide portions 371 with itsrespective associated slidable bar guide portion 351.

This has the advantage that the bar loader 300 additionally provides areliable and accurate guiding support for long bars or other elongatedworkpieces, which gives constant guiding support even when the workpiecespindles 30 are driven in the Z-direction.

FIGS. 14A and 14B exemplary illustrate schematic perspective views of amachine frame 10 for use at a multi-spindle turning machine 100according to yet another exemplary embodiment.

Different from the above exemplary embodiments, the machine frame 10 isadapted such that the upper side of the front frame portion 12 and theupper side of the back frame portion 13 are connected by an upper roofframe portion 16 which further increases and improves the stability andstiffness of the machine frame 10, e.g. in addition to the optional beamportion 14 and the frame portion 15 on the other side of the workspaceopposite to the front frame portion 12.

In addition, as exemplarily described below for FIGS. 15A and 15B, theconfiguration of FIGS. 14A and 14B has a modified turret configurationand spindle slide drive mechanism.

FIGS. 15A and 15B exemplarily illustrate schematic perspective views ofa drum/turret body 20 of the multi-spindle turning machine frame 10 ofFIGS. 14A and 14B.

The turret body 20 exemplarily has attached a front end portion 22 and aback end portion 21 which are the portions respectively supportedrotatably by the front frame portion 12 and the back frame portion 13 ofthe machine frame 10. The back end portion 21 attached to the turretbody 20 includes openings 26 through which each of the spindles 30 maybe supplied with workpieces (such as e.g. bars) from a backside of themulti-spindle turning machine 100.

The turret body 20 has, for each of the workpiece spindles 20, arespective longitudinal groove 23 extending longitudinally(Z-direction/longitudinal direction of the turret body 20) from thefront end portion 22 to the back end portion 21. The longitudinalgrooves 23 are exemplarily opened to the outer circumferential side ofthe turret body 20 so as to open to the space between the front frameportion 12 and the back frame portion 13 of the machine frame 10.

Exemplarily, the turret body 20 has, between each pair of adjacentgrooves 23, a respective ledge portion 24 extending longitudinally(Z-direction/longitudinal direction of the turret body 20) from thefront end portion 22 to the back end portion 21. Exemplarily, the numberof grooves 23 is the same as the number of longitudinal ledge portions24.

The spindle bodies 32 of the workpiece spindles 30 are exemplarilyguided in the respective longitudinal grooves 23 and supported by therespective spindle slide 31 which is arranged at an outercircumferential side of the turret body 20. Specifically, each spindleslide 31 is exemplarily guided, with guide elements 35, on thelongitudinal ledge portions 24 formed on the sides of the respectivegrooves 23.

Exemplarily, the slide drive mechanism includes a thread shaft 34 drivenby a drive 33 (drive motor). In FIGS. 15A and 15B, the drive 33 is notmounted to the spindle slide 31 but is mounted to the front end portion22 or a front portion of the turret body 20.

When rotatively driving the thread shaft 34 by way of the drive 33, therespective spindle slide 31 is driven in the longitudinal direction(Z-direction, axially with respect to the respective spindle axis) alongthe guiding ledges 24 so as to move the spindle body 32 of therespective workpiece spindle 30 in the longitudinal Z-direction (e.g.towards or away from the workspace) within the respective longitudinalgroove 23.

FIGS. 16A to 16C exemplarily illustrate schematic views of a drum(turret body 20) of the multi-spindle turning machine frame 10 anddetail views thereof for illustrating a drive mechanism thereof.

As previously described, the turret body 22 is rotatably supported aboutthe longitudinal rotational axis, in that a back-side end portion 21 ofthe turret body 20 (e.g. made as one piece with the turret body 20 orbeing attached to the turret body 20 at the back side) is rotatablysupported at the back frame portion 13 of the machine frame 10 and afront-side end portion 22 of the turret body 20 (e.g. made as one piecewith the turret body 20 or being attached to the turret body 20 at thefront side facing the workspace) is rotatably supported at the frontframe portion 12 of the machine frame 10.

For driving the rotational movement of the turret body 20, exemplarily atorque motor 80 is provided at the back frame portion 13 of the machineframe 10 (see e.g. FIG. 16A). The use of a torque motor has an advantagethat the rotation between machining positions of the workpiece spindles30 can be controlled efficiently, reliably, accurately and with quickresponse time by the numerical controller of the machine toolcontrolling the torque motor 80 as the drive for the rotational movementof the turret body 20.

As exemplarily illustrated in FIGS. 16B and 16C, the torque motorincludes a rotor 82 and a stator 81, wherein the rotor 82 is mounted ona circumferential portion of the back-side end portion 21 of the turretbody 20, and the stator 81 is mounted to the back frame portion 13 ofthe machine frame 10. The torque motor 80 is configured to drive therotational movement of the turret body 20 for movement of the workpiecespindles 30 between machining positions of the workpiece spindles 30.

By including the torque motor 80 into the rotatable support of the endportion of the turret body 20, a compact and efficient, power savingdrive mechanism can advantageously be provided.

Furthermore, any potential heat generated potentially by the drivemechanism is advantageously located far and separate from the frontframe portion 12 and the front end portion 22, in that the torque motor80 is separated by the air space between the frame portions 12 and 13and is located on the opposite end side portion of the turret body 20with respect to the end side portion 22 of the turret body 20 facing theworkspace.

Accordingly, an accuracy and precision of machining operations at theworkspace side can be improved since the torque motor 80 as potentialheat source, which might affect accuracy by thermal effects, is locatedon the opposite end side of the turret body 20 so that thermal effectsat the side facing the workspace close to the workpiece receivingportions of the workpiece spindles 30 and the tool post assemblies 40are advantageously minimized, while at the same time having theefficient, accurate and direct driving mechanism provided by the torquemotor 80.

To further enhance the accuracy of the machining operations and themovement control of the turret body 20, exemplarily, a positioningsystem 90 is circumferentially arranged around the front end portion ofthe turret body 20 facing the workspace at the position of the rotatablesupport of the front frame portion 12.

The positioning system 90 exemplarily includes a circumferentiallyarranged absolute encoder 91 for determining the rotational position ofthe turret body 20.

By detecting a rotational position of the turret body 20 by way of theposition signal from the absolute encoder, the driving control of thetorque motor 80 can be based on accurate feedback-control to accuratelyand precisely drive the turret body 20 to the rotational positionaccording to the intended machining position, for aligning the positionof the workpiece spindles 30 with the respective tool post assemblies40.

Since the positioning system is provided at the front side of the turretbody 10 at the front frame portion 12 facing directly the workspace andclose to the tool post assemblies 40, the accuracy and precision of thepositioning system is advantageously improved.

While using an absolute encoder 91 is a very preferred exemplaryembodiment, the present invention is not limited to the use of absoluteencoders as positioning detecting device, and other positioningdetecting devices may be used such as e.g. incremental encoders, e.g.measuring not the absolute position but the distance between themachining positions.

Furthermore, the positioning system 90 exemplarily includes plural brakemechanisms 92 (e.g. hydraulic, pneumatic and/or electric brakes)circumferentially arranged with respect to the front end portion of theturret body 20 facing the workspace at the position of the rotatablesupport of the front frame portion 12.

Accordingly, when the rotational position of the turret body 20 by wayof the position signal from the absolute encoder is detected to beaccurately and precisely located at the intended machining position, thebrake mechanisms 92 (position locking system) are actuated to fix andlock the rotational position of the turret body 20 in said intendedmachining position during the machining phase.

In some preferred aspects, a controller may be provided for controllinga machining of one or more workpieces received at the plurality ofworkpiece spindles 30, when the workpiece spindles 30 are positioned atrespective machining positions.

In some preferred aspects, the controller may be further configured tocontrol the torque motor 80 for controlling a rotational movement of theturret body 20 for indexing the workpiece spindles 30 between therespective machining positions and/or to control the position lockingmechanism (brake mechanisms 92) for locking the rotational position ofthe workpiece spindles in the machining positions during the machiningof the one or more workpieces.

In some preferred aspects, the controller may be configured to cut acontrol current of a control signal to the torque motor 80 after adriven rotation of the turret body 20 between the respective machiningpositions and to actuate the locking position locking mechanism (brakemechanisms 92) before controlling the machining of the one or moreworkpieces; and/or the controller may be configured to loosen the lockedposition locking mechanism (brake mechanisms 92) and to activate acontrol current of a control signal to the torque motor 80 for driving arotation of the turret body 20 to the next respective machiningpositions after machining of the one or more workpieces at the currentmachining positions.

At that time, during the machining phase, when workpieces are machinedat the machining positions by the driven rotation of the workpiecesspindles 30 and engaging the tools of the tool post assemblies 40, whenthe rotational position of the turret body 20 is fixed and locked by wayof the brake mechanisms 92, the drive signal to the torque motor can becut off and the torque motor is deenergized.

Accordingly, power can be saved and the heat generation by the torquemotor 80 and potential negative thermal effects on accuracy andprecision can be reduced even further.

Furthermore, as exemplarily shown in FIGS. 16B and 16C, the turret body20 is rotatably supported on the front and back frame portions 12 and 13by way of circumferentially arranged bearings B2 and B1, respectively.

As further shown in FIGS. 16B and 16C, and as previously described, thespindle body 32 of the respective workpiece spindles 30 have anintegrated drive 39 (built-in spindle motor) for driving the rotationalmovement of the respective workpiece spindle 30.

Furthermore, the spindle body 32 of the respective workpiece spindles 30further includes a clamping unit 38 configured to fixedly clamp a bar orother elongated workpiece received in the respective workpiece spindle30, wherein the clamping unit 38 exemplarily includes a hydraulicactuator for actuating the clamping and the unclamping of a bar or otherelongated workpiece. In other exemplary embodiments, the clamping unitcan be actuated by a hydraulic, pneumatic, mechanical, and/or electricalactuator.

FIG. 17 exemplary illustrates a schematic perspective view of anemergency brake system at a multi-spindle turning machine according toyet another exemplary embodiment.

It is to be noted that such emergency brake system (safety brake system)may exemplarily be provided at any of the above-mentioned embodiments ofmulti-spindle turning machines.

FIG. 17 exemplarily shows a back-side of the turret body 20 supported bythe back frame portion 13 of the machine frame 10. A rotational supportsystem for rotationally supporting the back-side portion 21 of theturret body 20 includes a fixed support ring structure 13 a attached tothe back frame portion 13 of the machine frame 10 and rotationallysupports a rotatable support ring structure 21 a attached to theback-side portion 21 of the turret body 20. The rotational supportsystem may further include the torque motor 80 as described exemplarilyabove.

Exemplarily, a brake disc 900 is attached to the rotatable support ringstructure 21 a and exemplarily three electric brakes 901, 902 and 903are attached to the fixed support ring structure 13 a, and each of theelectric brakes 901, 902 and 903 includes a respective brake clamp 900 aconfigured to engage with the brake disc 900 being attached to therotatable support ring structure 21 a. The invention is however notlimited to three brakes 901, 902 and 903 but may include one or morebrakes, and the invention is not limited to electric brakes but may alsoinclude hydraulically, electrically and/or pneumatically actuatedbrakes.

In preferred embodiments, the brake(s) 901, 902 and 903 are configuredas normally closed brakes, which are normally biased by a biasingmechanism (e.g. by respective spring mechanisms) into a closingdirection to engage with the brake disc 900 such as to fixedly hold thebrake disc 900 in the closed state. By electric (and/or pneumatic and/orhydraulic) actuation, the brakes 901, 902 and 903 can be opened tomovably release the engagement with the brake disc 900 so as to allowthe brake disc 900 and the turret body 20 to rotate about thelongitudinal axis (e.g. during machining operations).

Advantageously, if needed e.g. in a failure or collapse or fall down ofpower supply, the normally closed brakes can again lock engagement withthe brake disc 900 by closing the respective brake clamp 900 a due tothe normally-closing biasing force of the biasing mechanism.

Accordingly, in case of power supply failure or other emergencysituation, the safety (emergency) brake system, which is exemplarilyprovided at the back portion of the turret body 20, may act to initiatean emergency stop of the potentially rotating turret body 20.

By exemplary embodiments as described above, there are proposedbeneficial aspects and features to enhance the machining options of themulti-spindle turning machine, to provide a compact machine concept,allowing for more flexible, accurate, efficient and reliable machiningoperations, and/or to improve accuracy and/or stability of the machinetool.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and are not restrictive on the broad invention,and that the embodiments of invention are not limited to the specificconstructions and arrangements shown and described, since various otherchanges, combinations, omissions, modifications and substitutions, inaddition to those set forth in the above paragraphs, are possible.

Those skilled in the art will appreciate that various adaptations,modifications, and/or combination of the just described embodiments canbe configured without departing from the scope of disclosure of thepresent invention. Those skilled in the art will also appreciate, inview of this disclosure, that different embodiments of the inventiondescribed herein may be combined to form other embodiments of theinvention. Therefore, it is to be understood that, the invention may bepracticed other than as specifically described herein.

1. Machine tool, in particular multi-spindle turning machine,comprising: a machine frame, a turret body being rotatably supported bythe machine frame, a plurality of workpiece spindles being arranged onthe turret body, each of the workpiece spindles having a workpiecereceiving portion for receiving a respective workpiece on one side ofthe turret body facing a working space of the machine tool, a torquemotor for driving a rotation of the turret body, wherein the torquemotor is arranged at a back end portion of the turret body opposite tothe side of the turret body facing the working space of the machinetool, and a position locking mechanisim for locking a rotationalposition of the turret body is arranged at a front end portion of theturret body on the side of the turret body facing the working space ofthe machine tool.
 2. Machine tool according to claim 1, wherein aposition detecting mechanism for determining the rotational position ofthe turret body is arranged at the front end portion of the turret bodyon the side of the turret body facing the working space of the machinetool.
 3. Machine tool according to claim 2, wherein the positiondetecting mechanism includes an absolute encoder, in particular, whereinthe absolute encoder is arranged around the circumference of the frontend portion of the turret body.
 4. Machine tool according to claim 1,wherein the position locking mechanism includes one or more hydraulic,pneumatic and/or electric brakes.
 5. Machine tool according to claim 4,wherein the position locking mechanism is arranged around thecircumference of the front end portion of the turret body.
 6. Machinetool according to claim 1, wherein the machine frame includes a backframe portion rotatably supporting the back end portion of the turretbody and a front frame portion rotatably supporting the front endportion of the turret body, in particular wherein the turret body isrotatably supported by two bearings, one bearing being arranged on theback frame portion of the machine frame and another bearing beingarranged on the front frame portion of the machine frame.
 7. Machinetool according to claim 6, wherein a stator of the torque motor issupported by the back frame portion of the machine frame, and a rotor ofthe torque motor is arranged on the back end portion of the turret body.8. Machine tool according to claim 6, wherein the position lockingmechanism and/or a position detecting mechanism is mounted to the frontframe portion of the machine frame.
 9. Machine tool according to claim6, wherein a space is provided between the back frame portion and thefront end portion of the machine frame.
 10. Machine tool according toclaim 9, wherein the turret body has, for each workpiece spindle, alongitudinally extending groove portion for receiving the workpiecespindle, the grooves opening to the space provided between the backframe portion and the front end portion, and the turret body supports,for each workpiece spindle, a slide being guided on longitudinal slidesextending longitudinally with respect to the turret body and beingarranged on an outer side of the turret body adjacent to the respectivegroove portion.
 11. Machine tool according to claim 10, wherein theturret body supports, for each workpiece spindle, a drive mechanism fordriving a longitudinal linear movement of the respective slide of therespective workpiece spindle.
 12. Machine tool according to claim 11,wherein the drive mechanism is arranged on a front end portion of theturret body and/or on a back end portion of the turret body, and/or ahousing of the drive mechanism extends radially with respect to theturret body into the space provided between the back frame portion andthe front end portion.
 13. Machine tool according to claim 6, wherein asafety brake system is arranged on the back frame portion of the machineframe, the safety brake system including one or more electrically,pneumatically and/or hydraulically actuated brakes configured to brake arotational movement of the turret body, wherein in particular the safetybrake system includes one or more normally closed brakes being biasedinto a closing state by a biasing mechanism.
 14. Machine tool accordingto claim 1, comprising a controller for controlling a machining of oneor more workpieces received at the plurality of workpiece spindles, whenthe workpiece spindles are positioned at respective machining positions,the controller being further configured to control the torque motor forcontrolling a rotational movement of the turret body for indexing theworkpiece spindles between the respective machining positions and tocontrol the position locking mechanism for locking the rotationalposition of the workpiece spindles in the machining positions during themachining of the one or more workpieces.
 15. Machine tool according toclaim 14, wherein the controller is configured to cut a control currentof a control signal to the torque motor after a driven rotation of theturret body between the respective machining positions and to actuatethe locking position locking mechanism before controlling the machiningof the one or more workpieces; and/or the controller is configured toloosen the locked position locking mechanism and to activate a controlcurrent of a control signal to the torque motor for driving a rotationof the turret body to the next respective machining positions aftermachining of the one or more workpieces at the current machiningpositions.